griteater

That's always been my issue with the HRRR...by that time, the storm is right on top of you. It's really like a model you would use in the summer AM to help predict aftn thunderstorms (not sure how good it is with that)

Well that's more like it...can you tell us the timing of the heavy snow? As in Friday or is it later?

1km NAM from 1pm Sat to 5am Sun

Agree, the GFS does tend to run storms north a lot in the long range...it's a complete flip of its bias from the old days where it would suppress storms so much. Here's the infamous GFS run that sent the storm to Cuba that ended up hitting central GA > SC > SE NC big in Feb 2010

Either the GFS is a terrible model or we’re going to end up getting 2 rain storms along the east coast with a cold high in between during a big -AO / -NAO

We really, really suck at snow if we get a 1043 high over Lake Superior with behemoth cold air, and working perfectly in tandem with a coastal Miller A, and end up with ice (Euro run) Having said that, the Euro was a good run and went in the direction we want to go. Much better than the UKMET EPS Mean brings the bulk of the precip thru earlier, on Friday

UKMet doesn't look that good at hr144. Looks like the TPV in Canada is big and in no hurry to move southeast...surface high is stuck way up in NW Canada...and the SE ridge is flexing. Let's hope the Euro doesn't go in this direction later

It's because there are 2 waves on the GFS...one Friday morning that is wintry west of the Apps, and the second one tracks into colder air east of the Apps on Saturday morning.

It's possible if the TPV drops hard ahead of any waves that are digging into Mexico/Texas...we aren't there in the modeling yet though IMO except for the Canadian

The Canadian CMC brings a 1064mb high into Montana (that will verify!) and suppresses everything into oblivion...it has a light wintry mix right on the Gulf Coast in Houston / New Orleans / Pensacola, then later across S Georgia

Improved GFS run for sure. It looks almost exactly like that JMA run that was chastised, except it wasn't quite as deep with the wave digging into Mexico

JMA up close

Y'all have been looking at the wrong models. Today's JMA is lit

I would certainly lean Euro/EPS on getting the big picture right out in time given the heavy high latitude blocking pattern etc, regardless of what outcome it is showing for us. Not too worried about the current GFS unless the UKMET/Euro go in that direction. I think the changes with the weekend storm are a bit separate (smaller scale features that all of the models are struggling with driving storm track changes).

Yeah, think the biggest thing is the timing where the TPV has to drop down and drag the high pressure in behind it (or with it) before we have our storm move in. Last night's Euro and a few of the GFS runs yesterday nailed it. Others like this GFS run are a big miss

Ha I don't think that's the version of the storm that anyone's looking for

Comparison here of the big 3 ensemble means at day 7... GEFS has the least amount of ridging in the PNW and W Canada...is the slowest to move the tropospheric polar vortex (TPV) lobe to the southeast and out of south-central Canada, and has the largest amount of SE ridging. GEPS is the other end of the spectrum with its stronger western ridging...more TPV movement out of Canada...less SE ridging EPS is in between My personal preference for the biggest hit across the forum would be in between the EPS and GEPS

Historically, good things happen in the south when the AO approaches -6 standard deviation

Boom

If the wave digs into Mexico like that and it stays positive tilt, with a slight SE ridge flex, then yeah it’s just a long duration overrunning event

Last night’s run had Conway, SC in sleet at 22 degrees at 1pm Saturday

It’s going to be a long week. It gets colder past this point as the storm goes along. The western ridging was nice that run, but the cold vortex over South Central Canada just got hung up a little with its movement southeast. Big potential here

Yes, we want our storm wave (if it actually exists come go time ha) to dig south more which would give us that additional latitude to play with AND to slow it down so that the high has a chance to build in some ahead of time

^ Looks like the para is in between the GFS Reg and the CMC